Cracked bolt in water pump E85 M54

[Adam_F30]

2003 E85 2.5L manual 75k miles. Help! My engine thermostat was stuck open so I decided to take on the repair on my own and replace the water pump as well. Everything was going perfect until I was tightening the nuts on the water pump and one of the studs snapped off. At this moment, I was reminded that I should have checked the torque specs before the job. But it's too late for that. There is a small amount of the threaded stud still exposed from the block so I'm going to attempt to use vice grips to grab and gently remove the stud. I plan to replace it with an M6 1x20. My questions for the Zpost hivemind:
1. What is the best method for extracting a broken bolt in an engine block?
2. Is this threaded stud going into the block even able to be removed?
3. What are the torque specs for these bolts?
4. Do you think the water pump would still function properly with only 3 of the 4 bolts? (i think i know the answer to this one)

I followed the tutorial created by fbriggs from a while back and found it very helpful. Was able to go step by step until snapping the bolt. Worth noting, removing the fan gives you all the clearance you need to get this job done. Not sure if it was just a given or if people decided not to do it. After taking off the faring, its just two quick pins and unclipping a sensor to pull the fan.

Thanks in advance for the help!

[Adam_F30]

Just to follow up - after removing the pump to remove the broken bolt, there was enough still sticking out from the block that I used a set of vice grips to gently remove. Broken stem came right out after a few turns and I replaced it with an M6 1x25MM flanged bolt. Everything went smoothly reinstalling the pump and flushing the coolant. Happy to have this job behind me.

[drocket77]

Your lucky. I had a broken tensioner bolt on one of my other cars, and after fighting for a few hours, I finally broke down and welded a nut to the less than 1/16th inch that was left sticking out. I am not a good welder, and was afraid I was going to really mess the block up some how, or destroy the the hole, and have someone do a helix-coil job. But the welding trick worked.

[WickedNy]

If you have the room, I got this bolt and thread extractor from advanced auto...When I was putting the headers on my Silverado, a few of the studs snapped and one of them only had about an eighth of an inch sticking out from the block… This thing pulled everything out with zero problems

[WickedNy]

Just make sure you have the proper wrench sizes to back it out after you remove the thread… Because when this thing clamps you're not gonna un-spin it by hand...If it removed the threads on an 06 high mileage Chevy block, it should work